String formatTime(int seconds) {
  Duration duration = Duration(seconds: seconds);
  String formattedTime = '';
  String twoDigits(int n) => n.toString().padLeft(2, "0");
  String days = duration.inDays.toString();
  String hours = twoDigits(duration.inHours.remainder(24));
  String minutes = twoDigits(duration.inMinutes.remainder(60));
  String formattedSeconds = twoDigits(duration.inSeconds.remainder(60));
  if (duration.inDays != 0) formattedTime += '$days:';
  if (duration.inHours != 0) formattedTime += '$hours:';
  formattedTime += '$minutes:';
  formattedTime += formattedSeconds;
  return formattedTime;
}